Re: [Qemu-devel] [PATCH v5 0/8] modify boot order of guest, and take effect after rebooting

[Markus Armbruster <armbru@redhat.com>]

Gerd Hoffmann <kraxel@redhat.com> writes:

> On Di, 2014-08-26 at 09:07 +0000, Gonglei (Arei) wrote:
>> Hi, Gerd
>> 
>>  Nice to meet you again in maillist. :)
>> 
>> > -----Original Message-----
>> > From: Gerd Hoffmann [mailto:kraxel@redhat.com]
>> > Sent: Tuesday, August 26, 2014 2:36 PM
>> > Subject: Re: [PATCH v5 0/8] modify boot order of guest, and take effect after
>> > rebooting
>> > 
>> > > The patchsets add one qmp interface, and add an fw_cfg_machine_reset()
>> > > to achieve it.
>> > 
>> > > (qemu) set-bootindex ide0-0-1 1
>> > > The bootindex 1 has already been used
>> > 
>> > What happened to the idea to use qom-set instead?  I liked that
>> > suggestion.  Solves the suffix issue in a nice way.
>> > 
>> I have discussed with Makus about qom-set in pervious confabulation.
>> The main problem is that qom-set's function is simple, which just change
>> a device's property value, but not can do any other logic. In my case,
>> I should change global fw_boot_orde for devices's bootindex taking effect.
>
> Two options (also mentioned in the thread):
>
>   (1) Set/update bootindex on reset instead of realize/init.
>   (2) Switch the property from qdev to qom, then use the set
>       callback to also update the fw_cfg file.

Yes, please.  Even if it should make the implementation a bit more
complex.  Avoiding new ways to name things in external interfaces, such
as the suffix here, is worth some complication.